Peter Robertshaw is an archaeologist and professor of anthropology at California State University, San Bernardino. His research focuses on the later prehistory and precolonial history of sub-Saharan Africa and has been supported by the National Science Foundation, the National Geographic Society, and the National Endowment for the Humanities. Jill Rubalcaba began her working life as a college- and high-school mathematics teacher, all the while continuing to go to school to study more math, writing, and business. Later she worked as an engineer on the Patriot Missile. Ms. Rubalcaba is grateful to her children, Kelly and Dan, for showing her the joys of writing for children. Jill Rubalcaba is the author of several books for young adults, including The Wadjet Eye, Place in the Sun, and The Early Human World.